The present invention relates to a new and improved construction of a controlled deflection roll, also known in the art as a flexure adjusting roll or a roll with bending or sag compensation.
Generally speaking, the controlled deflection roll of the present development is of the type comprising a stationary support member or beam, a rotatable tubular roll shell which can be rotated about the stationary support member or beam and a plurality of hydrostatic pressure or support elements disposed between the rotatable tubular roll shell and the stationary support member or beam. These hydraulic pressure or support elements serve to support the rotatable tubular roll shell by means of a bearing surface and are sealingly movably guided transversely to the lengthwise axis of the stationary support member or beam by means of cylinder-piston guide systems or structure provided at the stationary support member or beam. The hydraulic pressure elements together with the cylinder-piston guide systems or structure define hydraulic pressure chambers, each of which is connected via at least one bore with the bearing surface and each hydraulic pressure chamber is also in flow connection or communication with a hydraulic pressure medium feed channel or conduit provided at the stationary support member or beam.
Controlled deflection rolls of the above-mentioned type are disclosed, for example, in U.S. Pat. No. 3,802,044 granted Apr. 9, 1974 and U.S. Pat. No. 3,885,283 granted May 27, 1975. In these described arrangements, the roll shell is either only supported by a plurality of pressure or support elements or, additionally, is supported at its ends by anti-friction or roller bearings. The pressure elements each comprise at least one hydrostatic bearing pocket in the area of the bearing surface. This hydrostatic bearing pocket is in flow communication or connection with the related cylinder or pressure chamber via at least one throttle bore extending through the pressure element. Through the throttle bores provided in the pressure elements, pressure fluid flows constantly from the stationary support member or beam in the direction of the roll shell, thus providing an elastic bearing or mounting of the roll shell at the stationary support member or beam. This, in turn, permits impulses acting upon the roll shell or the stationary support member or beam to be transformed into radial movement of these pressure elements in relation to each other.
By virtue of the throttle bores provided in the individual pressure elements, for some fields of application, it is possible to achieve sufficient damping of oscillations or vibrations occurring between the roll shell and the stationary support member or beam, whereby in particular, oscillations or vibrations of lower frequencies or larger amplitudes of the roll arrangement are damped. In many applications or for certain operating conditions in the presence of oscillations or vibrations occurring in a range of frequencies greater than, for example, 50 cycles per second, the damping of oscillations or vibrations can, however, be insufficient depending upon the construction and the dimensions of the roll arrangement, or else this damping effect is lost because the elasticity of the hydraulic pressure medium or that of the required feed or supply lines is essentially too great.